AB0297 FOOT AND ANKLE INVOLVEMENT IN RHEUMATOID ARTHRITIS IS ASSOCIATED WITH DISEASE ACTIVITY AND LESS INTENSIVE TREATMENT
Authors: A. Giollo, F. Frizzera, M. Salvato, F. Arru, F. Vesentini, M. Zen, A. Doria
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Foot and ankle involvement is not encompassed in joint counts routinely used for the management of rheumatoid arthritis (RA). For this reason, RA patients with foot and ankle involvement are at risk of undertreatment. <h3>Objectives</h3> To assess the prevalence of foot and ankle involvement in people with RA, and disease severity and RA-related comorbidities in this group. <h3>Methods</h3> This cross-sectional cohort study included all patients with established RA treated with biological and targeted synthetic disease-modifying anti-rheumatic drugs (b/tsDMARDs) at our Unit between 11/2014 and 12/2021. The following variables were recorded systematically: demographics, RA characteristics and joints involved, glucocorticoid therapy and dose, DMARDs, disease activity score in 28 joints with C-reactive protein (DAS28), and extra-articular manifestations (RA-related lung diseases, rheumatoid vasculitis, rheumatoid nodules, neuropathy, skin diseases, systemic symptoms including Felty's syndrome, and secondary Sjogren's syndrome). We also assessed comorbidities as recommended by EULAR (cardiovascular disease, gastrointestinal disease, depression, osteoporosis, malignancy and infections). We performed crude comparisons between patients with and without foot and ankle involvement by chi-squared test of association and independent T-tests. We used logistic regression to determine the odds ratio (OR) of the association between foot and ankle involvement and b/tsDMARDs, adjusting for DAS28, use of hydroxychloroquine (HCQ), and cardiovascular and lung disease. <h3>Results</h3> Among 1192 RA patients included in this study, foot or ankle involvement was reported in 469 (39%), equally distributed for age (mean±SD 61±13 years) and sex (females 82%). Age at onset, disease duration, erosions, seropositivity, use and dose of glucocorticoid therapy and methotrexate were similar between groups. DAS28 was significantly higher (4.3±1.2 vs 3.7±1.4, p&lt;0.0001) in RA patients with foot and ankle involvement, consistently with a significantly higher patient global assessment (55±22 vs 47±25 mm, p&lt;0.001), and number of tender joints (7±5 vs 5±5, p&lt;0.001) and swollen joints (4±4 vs 3±9, p&lt;0.001); the distribution of RA patients according to categories of disease activity was also significantly different between groups (p&lt;0.001; <b>Figure 1</b>). Nevertheless, the use of b/tsDMARDs was less intense in this group, as significantly fewer patients had received ≥2 b/tsDMARDs (28 vs 47%, p&lt;0.0001) despite similar disease duration. They also received more frequently hydroxychloroquine (55.2 vs 46.5%, p=0.003). These patients had significantly more cardiovascular (20.3 vs 15.8%, p=0.046) and lung disease (6.0 vs 2.9%, p=0.008). The body mass index was also significantly higher (25.6±6.5 vs 24.7±8.2 kg/m<sup>2</sup>, p=0.048), yet the proportion of patients with obesity was similar between groups (11.3% and 9.3%, respectively). Logistic regression confirmed the significant associations of foot and ankle involvement with a less intensive b/tsDMARDs use and higher disease activity (<b>Table 1</b>). <h3>Conclusion</h3> Nearly 40% of RA patients have foot and ankle involvement that associates with higher disease activity in other joints. However, we noticed low use of b/tsDMARDs in this group, a finding only partially explained by a substantially increased burden of RA-related cardiovascular and lung comorbidities. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> Alessandro Giollo Speakers bureau: Galapagos, Lilly, Consultant of: Galapagos, Novartis, Sandoz, Francesca Frizzera: None declared, Mariangela Salvato: None declared, Federico Arru: None declared, Filippo Vesentini: None declared, Margherita Zen: None declared, Andrea Doria: None declared.